Cartridge feeding mechanism



April 1, 1947.

H. w. RUVNDQUIST 2,418,428

CARTRIDGE FEEDING MECHANISM Filed Sept. 14, 1945 swam/Dom Hamming WHunflquisfi Patented Apr. 1, 1947 NITED STATES PATENT OFFICE 2,418,428CARTRIDGE FEEDING MECHANISM Application September 14, 1945 Serial No.616,332

3 Claims. 1

The present invention relates to an improvement in a feed mechanismparticularly adapted for use with, or as a part of, an automatic firearmof the character disclosed in U. S. Patents 1,525,065, 1,525,066, and1,692,328 issued in the name of John M. Browning, when using adisintegrating belt-link of the type disclosed in copending patentapplication Serial No. 483,520, filed April 17, 1943, in the name ofHarold T. Youngren (now Patent No. 2,392,280) and assigned to theassignee of this invention.

In the operation of automatic firearms of the above referred to type, ithas been found that the last link sometimes fails to engage in theguides and as a result the link does not pass out through the linkdischarge chute but instead passes under the stripper cams and lodgeswithin the feeding mechanism thereby making it necessary to open thefeed box and extract the misplaced link before another belt ofcartridges can be started through the feeding mechanism.

It is therefore an object of this invention to provide means whereby thelast link in a disintegrating-link belt of ammunition being fed throughthe gun will be positively aligned with, and engaged by, the feed guidesin the feed chute thereby assuring that the aforementioned link passesover the stripper cams and out of the discharge slot instead of beingdeflected under the stripper cams to lodge in the feeding mechanism.

The specific nature of the invention as well as other objects andadvantages thereof will clearly appear from a description of a preferredembodiment as shown in the accompanying drawings in which:

Fig. 1 is a perspective view of the cartridge entering side of the feedbox of an automatic cannon showing the end of a link belt of cartridgesin feeding relationship to such box.

Fig. 2 is a cross-sectional View of the feed box of Fig. 1 showingparticularly the relationship of the last cartridge and link of thelinked belt of cartridges with respect to the feed box; and

Fig. 3 is a side elevational view of a cartridge positioning springconstructed in accordance with this invention for use in the feed box ofFig. 1.

Disintegrating links I0, used with the above mentioned cannon, comprisea single loop portion I I and a double loop portion l2, joined by abight portion l3 (Fig. 2). These loop portions are of generallysemi-cylindrical form, the double loops being of slightly larger radiusthan the single loop. Single loop H has a tab [4 on each edge, anddouble loops l2 each have a tab I5 on their outer edges. Both pairs oftabs are equidistant outwardly from, and parallel to, a plane tangent tothe curved side of both single and double loops, the tabs in each pairextending oppositely from each other and parallel to the axis ofcurvature of the corresponding loop.

Single loop H is slightly narrower than the space between double loopsI2, so that when the links ill and cartridges H are assembled into abelt, tabs I4 on single loops l I rest on double loops I2 and tabs IE ondouble loops l2 extend outwardly, parallel to the axis of the encircledcartridge, for a purpose to be shown later. This relationship is withthe links above the cartridges.

Double loops l2 fit so loosely around the cartridge that the link canrotate freely within the range of the angular clearance permitted by thesingle loop II of the adjacent interlocking link, which loop tightlyholds the cartridge in a resilient grip.

A feed box 20, suitably mounted on the cannon (not shown), has a sidewall 2|. The side wall 2| is cut away to form a cartridge feed slot 23(Fig. 2). Stripper cams 26 are provided within feed box 20 facing feedslot 23 as shown in Fig. 2.

A feed chute 29 is attached by bolts 30 to the side wall 2| of the feedbox 20 covering teed slot 23, the chute being so disposed that a belt ofammunition fed therethrough will be properly aligned with the strippercams 26 when it enters the feed box 20.

Feed chute 29 has a floor 3| and a roof 36 (Fig. 2). The outer portionof fioor 3| curves outwardly and downwardly forming a lip 32. Ribs 33are provided in the floor 3| to act as bearing surfaces for thecartridges being fed therethrough.

The roof 36 of chute 29 curves outwardly and upwardly at the outer edgeto form a lip 31 generally above lip 32 on floor 3|. These lips 32 and31 serve to guide the ammunition belt into chute 29. Two guides (onlyone of which is shown in Fig. 2) are secured in spaced parallelrelation, to the underside of roof 36, in alignment with stripper cams26. The guides 38 communicate with guides 34 secured in dependingrelation to the roof of the interior of the feed box.

As a belt of cartridges is drawn through the feed chute 29, bearing ribs33 support the car tridges at the required level so that tabs [5 ondouble loops l2 slide into guides 38 and the belt of cartridges isdelivered into the feeding mechanism in proper alignment with strippercams 2B. In this relation, tabs l5 pass on top of stripper cams 26,whereas the cartridges are engaged by the underside of the cams andthereby stripped 3 from the belt links l and forced down into theloading mechanism (not shown). The structure thus far described isconventional and is more particularly described in U. S. Patents1,525,065, 1,525,066, and 1,692,328 to John M. Browning.

As the last cartridge enters feed chute 29, the last link, which has itsdouble loop I2 around the cartridge and its single loop II empty, willhang downward from the cartridge, as shown in Fig. 1, there being nosupport under the empty single loop H. In this position the tabs I5 ofsuch last link would not be engaged by guides 38 but would instead passunder the guides and stripper cams, and, consequently, would be cammeddownward by the stripper cams 26 and lodge in the loading mechanism (notshown) To prevent this occurrence, a leaf spring 4|] of generallyarcuate shape (Fig. 3) is mounted in feed chute 29 as shown in Fig. 2.One end of this spring is suitably secured to lower lip 32 as by rivets45 and extends inwardly and upwardly above the floor 3! of chute 29,being constructed so that while it freely deflects under the weight of acartridge to allow passage of the cartridges thereover, it normallyextends high enough to engage the bight l3 of the last link, and is ofsumcient stiffness to resiliently cam the link upwardly, in pivotalmotion around the last cartridge, into a horizontal position in whichtabs [5 on double lops l2 are adjacent the roof 3B of chute 29 and inproper position to be engaged by guides 38 and thereby delivered tostripping cams 26 in position so that the link will be stripped from thecartridge engaged in the double loops [2, and finally discharged throughthe conventional ejection slot (not shown).

The inwardly projecting end, of. the spring 49 is provided with anangularly bent portion 46. The bent portion 46 passes freely downwardlythrough a hole 41 in feed chute'fioor 3| when the spring 40 is depressedby a cartridge or link but retains the spring 40 in operative positionwithin the empty feed chute by engagement with the edge of hole 41.

It is therefore apparent that this invention provides simple, yeteffective means whereby the last link in a disintegrating-link belt ofcartridges is aligned for engagement by the guides and stripper cams sothat ejection of the link through the ejection slot is assured.

I claim:

1. In combination with a machine gun having a feed chute secured to thegun and having guides therein arranged to support for movementtherethrough the links of a disintegrating link belt of cartridges, theimprovement comprising, a leaf type spring, one end of which is fastenedto the base of the feed chute, said spring projecting upwardly intothe'path of feeding movement of the belt of cartridges, the free end ofsaid spring being constructed and arranged to engage the bottom portionof each successive link whereby said spring biases the last link intoproper position for engagement by said guides.

2. In combination with a machine gun having a feed chute secured to thegun and having guides therein arranged to support for movementtherethrough the links of a distintegrating link belt of cartridges, theimprovement comprising, a leaf type spring, one end of which is fastenedto the base of the feed chute, said spring projecting upwardly andangularly forward from its secured end in the direction of feedingmovement of the belt of cartridges whereby the free end of said springlies in the path of feeding movement of the belt of cartridges, the freeend of said spring being constructed and arranged to engage the bottomportion of each successive link whereby said spring biases the last linkinto proper position for engagement by said guides.

3. The combination defined in claim 1 wherein the extreme free endportion of said spring is constructed and arranged to engage the feedchute to retain said spring in operative position in the chute in theabsence of cartridge links therein.

HENNING WM. RUNDQUIST.

